distribution of magnetic fields in the quiet-sun internetwork areas has been affected by weak polarization (in particular stokes q and u) signals. to improve the signal-to-noise ratio (snr) of the weak polarization signals, several approaches, including temporal integrations, have been proposed in the literature. in this study, we aim to investigate a proper temporal-integration time with which...

We discuss a new technique of studying magnetic fields in diffuse astrophysical media, e.g. interstellar and intergalactic gas/plasma. This technique is based on the angular momentum alignment of atoms and ions in their ground or metastable states. As the life-time of atoms in such states is long, the alignment induced by anisotropic radiation is susceptible to weak magnetic fields (1G ∼ > B ∼ ...

Distribution of magnetic fields in the quiet-Sun internetwork areas has been affected by weak polarization (in particular Stokes Q and U) signals. To improve the signal-to-noise ratio (SNR) of the weak polarization signals, several approaches, including temporal integrations, have been proposed in the literature. In this study, we aim to investigate a proper temporal-integration time with which...

Circularly polarized electric fields incident on subwavelength apertures produce near-field phase singularities with phase vorticity +/-1 depending on the polarization handedness. These near-field phase singularities combine with those associated with orbital angular momentum and result in polarization-dependent transmission. We produce arbitrary phase vorticity in the longitudinal component of...

Deterministic sources of polarization entangled photon pairs on demand are considered as important building block for quantum communication technology. It has been demonstrated that semiconductor quantum dots (QDs), exhibiting a sufficiently small excitonic fine structure splitting (FSS) can be used as triggered, on-chip sources of polarization entangled photon pairs. As-grown QDs usually do no...

In complex scalar fields, singularities of the phase (optical vortices, wavefront dislocations) are lines in space, or points in the plane, where the wave amplitude vanishes. Phase singularities are illustrated by zeros in edge diffraction and amphidromies in the heights of the tides. In complex vector waves, there are two sorts of polarization singularity. The polarization is purely circular o...

The performance of solution cross-polarization using trains of shaped pulses on two channels is investigated by computer simulation and experiment. It is determined that a Waltz modulation pattern of Gaussian pulses of individual flip angles of 225°, issued to two coupled spins simulatneously, yields excellent coherence transfer with good phasing behavior. Simulations and experimental verificat...

One of the most informative techniques of studying magnetic fields in molecular clouds is based on the use of starlight polarization and polarized emission arising from aligned dust. How reliable the interpretation of the polarization maps in terms of magnetic fields is the issue that the grain alignment theory addresses. I briefly review basic physical processes involved in grain alignment.

Low detection sensitivity stemming from the weak polarization of nuclear spins is a primary limitation of magnetic resonance spectroscopy and imaging. Methods have been developed to enhance nuclear spin polarization but they typically require high magnetic fields, cryogenic temperatures or sample transfer between magnets. Here we report bulk, room-temperature hyperpolarization of (13)C nuclear ...

We have used the University of Tasmania Mt Pleasant 26-m radio telescope to investigate the polarisation characteristics of a sample of strong 6.7GHz methanol masers, the first spectral line polarisation observations to be undertaken with this instrument. As part of this process we have developed a new technique for calibrating linear polarisation spectral line observations. This calibration me...